HP Xw8200 HP Workstation xw8200 Service and Technical Reference Guide (Complet - Page 150

NOTE The industry standard, 1.44-MB diskette drive has its own separate channel and is not included as a part of the maximum four drives. Any drive attached to a controller must have a drive designation. If only a single drive is connected to a controller and its jumper is in the cable-select position, it is designated as the Master Drive (Drive/Device 0) by its attachment to the Drive/Device 0 cable position. If two cable-selected drives are connected to a single controller, one will be designated by its attachment to the cable as the Master (Drive/Device 0) and the other as Slave (Drive/Device 1). For optimal performance of a workstation system, all drives must be attached to the ATA controllers in a specified sequence. This sequence is determined by the device class of the drives and by specific attach sequence rules. Device Classes To determine the best drive attach sequence, ATA/ATAPI drives are segregated into four different classes based on the bandwidth demands they place on an ATA controller. The most demanding devices are in Class 1 and the least demanding are in Class 4. Table C-1 Device Classes Class 1 Hard Drives Class 2 High Speed Optical Drives ATA-100 ATA-66 ATA-33 DVD DVD-CD R/W Class 3 Optical Storage Drives Class 4 Magnetic Storage Drives R/W CD-ROM CD-ROM LS-120 Tape Zip General Attach Guidelines „ The lower the device class number, the faster the device and the more bandwidth required. „ Drives installed in the Device 0 positions on both the primary and secondary controllers receive the greatest possible bandwidth. „ The bootable ATA hard drive should always be installed on the primary controller in the Device 0 position. Attach Sequence Rules by Class Priority Drives should be attached in the sequence shown for optimum performance starting at position 1. 4 1 3 2 Primary Controller* 4 1 Secondary Controller Figure C-1 Installing Drive Order 3 2 Device 1 Device 0 150 ULTRA ATA DEVICES